Back when those were pertinent to the sesquicentennial, I discussed the coastal defenses around Savannah (part 1 and part 2). I touched upon some of the improvements built on Whitemarsh Island early in 1864. (And at some time after these 150ths are over, I’ll return to discuss them in more detail.) But all of those works were overtaken by events in December 1864, being useless for the situation at Savannah. It was the land-facing and rear guard defenses that were critical to the city’s defense from Sherman’s advance. As the “Marching through Georgia” narrative requires some mention of those defenses, let me walk through the major elements of the works.

If you like cartoons, maybe Robert Knox Sneden’s map is to your liking:

I’m sure Sneden was good at his work, but I find his maps too busy and lean on scaling. I prefer the work of Captain Orlando Poe:

Poe drafted this map to accompany Sherman’s official report on the campaign, and for the most part it is a great representation how the defenses stood in December 1864. However, there are some works not depicted on the map. Still, the best primary source on the subject. Allow me to break these down by section to explain the “layers” defending Savannah.

First, leaving the discussion of the coastal and river defenses aside, there is the inner defenses that ringed Savannah. Confederates began construction of these in 1862. Work picked up during General P.G.T. Beauregard’s tenure in command. Looking close at Poe’s map, that line covered the east and south sides of the city, between one and two miles out. (and ignore for the moment the “blue” inner ring, as that depicts Federal positions after the surrender):

The line of works started at Fort Boggs on the east side of Savannah overlooking the river, with the general arrangement of a star fort. In March 1863, Fort Boggs held ten 32-pdr smoothbores, three 3-inch rifles, one 6-pdr gun, a 24-pdr howitzer, a 12-pdr howitzer, and two 10-inch mortars. By May 1864, the armament was one 10-inch columbiad, eleven 32-pdrs, and two 10-inch mortars. (The site of Fort Boggs on the grounds of the Savannah Country Club.)

The next major work in the line was Fort Brown, forming a salient where the lines turned to fit the terrain to the south of Fort Boggs. Fort Brown had five 32-pdrs and one 18-pdr in March 1863. Within a year that armament was reduced, and specifics were not mentioned in returns for 1864. Between Forts Boggs and Brown was a crémaillère line with nine gun platforms.

Fort Mercer stood further south at the southeast corner of the line. In March 1864 it contained two 32-pdrs, two 8-inch siege howitzers, and one 24-pdr howitzer. Between Forts Brown and Mercer were seven numbered Lunettes (Nos. 19 to 25). To the right of Fort Mercer ran the south-facing line with Lunettes Nos. 1 to 18. The lunettes were armed with an assortment of carronades, flank howitzers, or smoothbore siege guns in March 1863. Within a year, many of those guns were relocated elsewhere to defend points closer to the coast.

Lunette No. 1 sat near the Savannah Canal. From there back to the river, the Confederates constructed no lines. Low ground there made an attack unlikely. For what it is worth, in 1779, the British also left that side of Savannah largely undefended in their successful defense of the city.

An open work, named Battery Harrison, lay beyond these lines and protected the approaches from the Vernon River. Further south was a string of batteries located on ground dominating the marshes:

While constructed to prevent landings from sea-borne forces, in the first weeks of December these works also anchored the south end of the defenses. To get past these works, the Federals either had to force a landing or push through Middle Marsh that extended to their right, back to the railroad. Of course none of these were close enough to support Fort McAllister on the Ogeechee River. That bastion, while effectively the cork in the bottle preventing Sherman’s resupply, was isolated from the rest of the defense.

Until Sherman’s march, any approach to the city from the west was unlikely. Not only were no Federal forces able to strike from that direction (until December 1864, of course), but the swamps, marshes, rice fields, and rivers served as a natural defense. To deter raids on the Savannah & Gulf Railroad, picket posts watched the line south to the Altamaha River. The crossing over the Ogeechee River, just downstream from King’s Bridge, was posted, but without any works or batteries (as Fort McAllister kept it safe from Federal raiders). Otherwise there were no works of significance to the west of the city.

As it became clear Sherman was marching towards Savannah, Confederate leaders put renewed efforts to defend from the west. In the first days of December a line went up from the Savannah River reaching down to the Savannah & Gulf Railroad:

Fort Hardeman anchored the right end of the line and covered the channel between Hutchinson’s Island and the mainland. Likely this fort received the most attention from the Confederates as it was described as well laid with dep ditches. In addition to an abatis, the outer obstacles included wire strung across stakes. The fort held ten guns, some of which were siege caliber.

The line south from Fort Hardeman featured at least one unnamed battery. Where the line crossed the Georgia Central Railroad, a gun mounted on a flat-car was the main armament of Battery McBeth. Nearby Battery Acee covered Shaw’s Dam on the canal with a 12-pdr gun. Another Napoleon gun was in an unnamed battery further down the line. Battery Barnes faced an expanse of rice fields with two 32-pdrs, two Napoleons, and two 12-pdr howitzers. Linking with Battery Barnes was a battery on Pine Point. Battery Jones on the Darien Road held two 32-pdrs, four Napoleons, a Parrott rifle, and a carronade. Finally there are references to a battery along the Savannah & Gulf Railroad where the line passed Middle Marsh.

The line was not idea, and had several bad angles. But it held some formidable armament. Though we should consider most of the heaviest guns were still positioned to face the channels leading to the sea. Federal tallies, after the fall of Savannah, counted right at 200 guns of all calibers. In addition to the garrison guns, howitzers, mortars, and carronades, the Confederates had 48 field guns in the lines. By most accounts the Confederates had sufficient ammunition for a siege. The Federals recorded the capture of over 21,00 rounds, mostly smoothbore, with the fall of Savannah. On the other hand, the Confederate defenders lacked time to prepare the works to withstand a lengthy siege.

The Federal gunners on the opposite side had around 65 guns. The largest guns were one battery of 20-pdrs. Sherman would call upon the Department of the South for other heavy guns, as he confronted the line. But for the most part, the Federal success on the line at Savannah depended on shovels and siege-craft… and a lot of bluff to convince Lieutenant-General William Hardee the line was untenable.